


Filling in the Gaps

by alkalinePessimist



Category: Homestuck
Genre: Biting, Established Relationship, Heatfic, Humanstuck, Knotting, M/M, Mating Cycles/In Heat, Plot What Plot/Porn Without Plot, Trans Character, Trans Karkat Vantas, Trans Male Character, c'mon you guys focus, lol 'whoops', unprotected sex
Language: English
Status: Completed
Published: 2018-10-01
Updated: 2018-10-01
Packaged: 2019-07-21 01:51:48
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 2,457
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16150043
Author URL: https://archiveofourown.org/users/alkalinePessimist/pseuds/alkalinePessimist
Summary: Prompt from the Karkat Thirst Server: Karkat starts his heat in the middle of the work day, so he goes home early to jump on Dave.





	Filling in the Gaps

**Author's Note:**

> Live Jammed in the Karkat Thirst Server! https://discord.gg/zqwgShC
> 
> //Edited: 10/13/2018

Today was going wonderfully.

You had woken up ten minutes earlier than you had expected to, only feeling mildly tired, which gave you time to cuddle up to Dave before you had to leave. Brushing his hair out of his face, you smiled at him. He always looked so at peace when he was sleeping, and it was still a novel experience that you could catch him in this state, that he trusted you enough to let his guard down like this.

But what were mates for if not to love and trust?

You had regretfully detangled yourself from your lover at the sound of your alarm, Dave mumbling and curling into your warm side of the bed, nuzzling your pillow. You couldn’t help but take a picture of the sight.

After deciding to forgo your binder, you had thrown on some loose-fitting clothes and headed out to the coffeeshop down the street, a full cup of coffee in hand.

You realize the irony of taking your homemade coffee to your local coffeeshop, but who gives a fuck about that anymore after they’ve listened to Dave go on and on about ‘irony’.

You had only just sat down with your editor for your monthly in-person meeting before you began to feel the warmth twisting in your gut.

Thinking nothing of it, you shifted in your seat and tried to refocus on your editor. “No, I already rewrote that scene twenty times, if I condense it any more it’ll lose any amount of character building that the scene was originally put there for.” A wave of heat rolled over your body, followed up with a sickly clamminess. “If it’s not working then we’ll just have to move it or scrap it altogether.”

She pursed her lips at you, making a small note in her opened notepad. “Perhaps we could…”

You lost the rest of the sentence when the tension building in your stomach burst, sending the heat downward to your crotch. Your legs jerked under the table and your grip tightened on your coffee cup, white knuckling so hard you thought it might shatter. _Fuck._

Sucking in a breath, you looked up at your editor, who had apparently not noticed your predicament and was pulling out one of your more recent drafts for reference.

“Rosa, I’m sorry but I’m going to have to cancel the meeting today.” You squeaked out. Her head rose up from where she was pouring over your draft to look at you, frowning. Before she could protest, you jerkily stood. “I completely forgot I had plans with my mate today, I have to go. I’ll email you to reschedule, bye!” You were already out the door by the time you had gotten to ‘email’.

Gripping your coffee cup to stop your hands from shaking, you practically bolted back to your apartment, heat pooling in between your legs. You knew you wouldn’t be able to stop it, and soon you wouldn’t even be able to use your legs, you had to get back to Dave. _Now_.

You jerked the door to your building open and made for the stairs.

Jesus SHIT why did you two decide to live on the top floor? About halfway up you started gripping the handrail for support, baring your teeth in what you hoped passed for a grin to one of your neighbors going down.

The handrail could only help you so much.

Two floors away from the your own, your legs buckled, and your body collapsed on the stairs. Luckily, you still had a death grip on the railing, so you didn’t go tumbling down them, much as Dave would find that fucking hilarious.

_Dave…._

You whimpered as you thought of him, your legs convulsing, instinctively trying to put pressure on your clit. God you wished he were here, if he was, he’d… he’d…

_He’d fuck you over the railing is what he’d do._

Your gasping breath echoed in the stairwell, and you hooked one of your legs around the lower bar of the railing. God he would just _rail_  you until you came, pounding into you over and over until you had no choice but to grab the rails on either side of yourself to keep from looking down, down, down…

Your phone buzzed in your pocket, startling you out of your haze. You dropped your head on the concrete, panting, and you pulled your phone out of your pocket.

 **From Dave:** hey babe woke up and you were gone

 **From Dave:** hope your meeting goes well

 **From Dave:** make that ca$h money baby

 **From Dave:** ill have lunch ready by the time you get back okay babe

 **From Dave:** love you  <3

Fuck, you had to get to him, working yourself into a frenzy thirty feet away wasn’t going to do you any favors.

You gritted your teeth and painstakingly hauled yourself up. Just two more flights.

Making your way up, your gut started to cramp, and your breath is coming faster now, your fingers slipping on the handle of the door as you fall through it.

Fuck yes, your apartment.

Shakily, you felt around your body for your key, and belatedly realize you lost your coffee cup somewhere along the way. Whatever, you’ll go back for it… later.

Nevermind that 'later' may as well be a week from now after the heat had worn off.

Scrabbling at the door, thoughts of your lost cup evaporated from your mind as you finally got the door open. Slamming it shut bodily behind you, you locked it again and stumbled into the living room where you could hear cartoons on the TV.

There he was, sitting on the couch in his flannel pajama pants and nothing else, eating a bowl of Lucky Charms.

You groaned breathlessly and rushed around the couch, eager to get your hands on him.

He startled at your sudden appearance, setting the bowl down with a frown on his face. “KarkMMPH.”

There was absolutely _no time_  for talking, so you just jumped in and smashed your face to his, hoping he’d get the message.

Pulling away, Dave gasped. “Karkat, wha-” Apparently not. You surged forward again, this time shoving your tongue into Dave’s mouth and grinding your crotch down onto his, a whine in the back of your throat. His hands flew up to twist in the back of your sweater, and _fuuuuuck yes,_ he was grinding back.

Your whole body shuddered, and you broke the kiss to moan, your underwear completely soaked through and being pressed up wetly against your crotch was getting uncomfortable. “Dave,” you gasped as he started nibbling along your neck, getting a sense of your smell. You shuddered as he realized what this was and growled. “Dave please, I _fuck,_ fuckfuck, I need you. Dave please-”

Dave clamped his jaws into your neck and your whole body seized, a howl tearing out of your throat.

Grabbing you by the ass, Dave stood, picking you up and flipping your positions. Standing back, he took a moment to watch you as you writhed, anxious to get a move on already. The way his eyes burned into you did things to your stomach and somehow you were even more turned on than before.

  
“God, you’re so beautiful, Kat.” You whine, trying to pull your legs together to get something, anything, but Dave’s hands wrapped around your thighs and held you open. “I mean it, you really are. Beautiful and handsome and-”

“Dave for the love of _all that is holy_  can you please just-” You cut yourself off with another whine, hips shifting on the couch.

Dave grinned at you, his fangs coated in a bit of your blood from where he marked you, and you outright moaned. “As my perfect mate commands.” Dave went to undo your pants, ripping them off swiftly along with your boxers, and you shivered as the cold air rushed in. Dave slipped his own pants down to his knees and moved back into position, hands spreading your thighs wide apart, his grinning face looming right over your own.

You were shivering in anticipation, but Dave just kept grinning smugly at you. You opened your mouth to beg some more, “Da-” when his grip on your thighs tighten and he pushed himself into you, effectively cutting you off. Your hips hitched as he filled you, your legs straining against his grip, but he laughed and pulled out again. You whined at the empty feeling, but it didn’t last as he pushed quickly back in, snapping his hips with quick consistency. Your brain shut off and all you could think was _Dave Dave Dave Dave._ You wrapped your hands around his neck and whined, pleading with him to come down to you, and with a groan, he obliged.

Leaning down, he seemed to spread you apart even more, and you wrapped your arms fully around his neck while he buried his face in your shoulder. At this angle, he couldn’t get as deep, but he _could_ speed up, setting a brutalizing pace with shorter strokes, and you arched your back into him.

Panting into your shoulder, Dave started to nibble and lick once again, sucking hard, trying to mark you as much as possible. Letting go of your legs, he propped himself up on his elbows, framing your face and setting his forehead against yours.

With better leverage, he reached deeper in you, and he nuzzled his face against yours, the contrast of what was happening down below and the sweet way he showed you he loved you up top was making your head spin. Clutching at his shoulders, you shifted your hips up to meet his, and his hips stuttered.

“Fuck, Karkat.” He looked at you hungrily, keeping pace with the rhythm you set, sliding deeper and deeper with each thrust, his knot starting to swell. “You know I love you, don’t you?” He was breathlessly whispering at you now. “You know your _mine._ ” He emphasized the statement with a particularly powerful thrust.

Your eyes rolled in your head, a mantra of “ _Y_ _ours, yours, yours_ ” pouring out of your mouth, and he leaned down to press his lips against your bared neck, speeding back up.

Your legs trembled as he hit your G-spot, and you screamed and clawed at his shoulders, tightening around him as his knot finally popped in, locking his dick into place. Your mind went numb, and all you were conscious of was the feeling of being filled.

___

Coming to, you felt your mate nuzzling and licking at your neck, still buried inside you. You sighed, and with a heavy hand, you pulled your fingers through his hair. “Dave.” You mumbled, still kind of out of it. He hummed in response, not stopping his doting actions. “Dave,” you said a little louder. “Did you come _in_ me?”

He froze and looked up at you sheepishly. “Uh, whoops?”

You groaned and let your head fall back against the couch. “m gonna have to shower now you ass.” Showering in between heat induced fucking was going to be more exhausting than the actual heat itself.

“M’sorry Kat. I’ll wear a condom for the rest of the week, I promise.” He kissed you on the cheek, then shifted to maneuver himself out of you, and you jerked and gasped.

Dave laughed at you and pulled himself completely free, and you could feel the gaping loss uncomfortably between your legs. He didn’t say a word and he scooped you up in his arms, carrying you across your apartment to the bathroom. You nuzzled your face into his chest, comforted by his scent and the way he didn’t hesitate to take care of you. For all your complaining about him, you loved him dearly.

He set you down on the “old man bench” as he calls it - and what the fuck was wrong with having a bench in the shower? It’s fucking practical Strider! - inside one end of the tub and got the water running hot for a shower, stepping in as well after it had warmed up. After he washed himself – wiggling his ass in your face enough to make you laugh at him – he turned his attentions towards you, helping you stand and clean the stickiness away.

You shuddered as he cleaned the come out of your front, and god _damn_ was your heat in full swing. You moaned as he pressed up against your back, caging his arms around you. “We’re already in the shower, Kat. Might as well, hmm?”

Your only reply was a shudder as you leaned back into his grasp. He guided you gently over to the tiled wall, the abrupt coldness shocking you out of your dazed state a bit as Dave ground his dick against your ass, toying with your folds from the front.

Leaning your head against the tile, you spread your legs and angled your hips out for him. The heat coiled over you, warming the wall you were pressed against as he slid home.

You moaned, hitching yourself up on his cock, trying to get it deeper, and Dave starts fucking you slowly, with long strokes. He buried his face in your shoulder as he moved, and you tried to leverage yourself against the wall to get more force behind each thrust. All it accomplished was you scrambling for a hold until Dave grabbed your wrists and pinned them above your head, getting your message and picking up the pace.

Dave grunted and shifted forward, pace now drilling into you, and as you squirmed and moaned breathlessly, the angle hit just the right spot inside of you, and you choked on air. You tried to beg Dave to catch up with you around the choked feeling in your throat, but his knot came right behind it, popping into place once again and locking Dave’s dick right up against your G-spot. Your vision whited out as you came, body clenching up against the warm tiles.

You didn’t even come to completely when Dave pulled out for the second time that day. You hummed as he cleaned you out once again, squirming against the now cold water, but soon you were whisked away again, out of the shower and settled into the comfy softness of your bed. You half mindedly roll over to bury your face in Dave’s pillow, eager for his scent after the cleansing shower, but found actual Dave in its spot.

What a much better option.

You snuggled up to your mate and sighed contentedly.

“Love you, Kat.”

Dave’s voice was soft as you drifted off to sleep, but you managed to place a soft kiss against his neck in response before fully drifting off.


End file.
